Restore Peak Performance to Your GM Vehicle
Is your 2017 Cadillac Escalade, Chevy Silverado, or GMC Sierra suffering from frustrating issues like a persistent check engine light, random stalling, poor fuel mileage, or a dreaded no-start condition? The Engine Control Module (ECM) is the sophisticated brain of your vehicle’s powertrain, and when it fails, it can cause a cascade of problems. This isn’t just an inconvenience; it’s a critical failure that compromises your vehicle’s reliability and performance. This listing offers a direct, reliable solution: a genuine GM Engine Control Module, part number 12678815, delivered to your door already programmed with the latest factory software specific to your vehicle’s VIN.
Case Study: A Tricky Diagnosis
I remember a 2017 Silverado 1500 that came into my shop with a ghost of a problem. The owner complained of intermittent stalling at stoplights and a random no-start that would resolve itself after a few tries. We couldn’t replicate it consistently. We checked the fuel pump, ignition system, and battery—all tested fine. The scanner showed a few lost communication codes (U0100) but nothing pointing definitively to one component. Experience told me to look at the network’s master controller: the ECM. After swapping in a pre-programmed module like this one, the truck ran flawlessly. The internal circuitry of the original ECM was failing under certain thermal conditions, a common issue I’ve seen dozens of times. This pre-programmed module was the key to a fast, accurate, and cost-effective repair.
Is Your GM Vehicle Showing These Signs?
A failing ECM can manifest in various ways. If you’re experiencing any of the following, this module is likely the solution you need. In my 20+ years of diagnostics, these are the most common indicators of a compromised 2017 Escalade Engine Module or its equivalent in other GM models.
- ✔ Check Engine Light: Often with internal processor fault codes like P0601, P0603, P0604, or P0606.
- ✔ Engine Stalling or Misfiring: The engine may shut off unexpectedly or run rough.
- ✔ No-Start Condition: The engine cranks but refuses to start due to a lack of fuel or spark commands.
- ✔ Poor Performance & Fuel Economy: Inaccurate sensor readings and calculations lead to inefficient engine operation.
- ✔ Transmission Shifting Problems: The ECM communicates with the TCM, and a fault can cause harsh or erratic shifting.
- ✔ Communication Errors: Your scanner may show a ‘No Communication’ error with the engine module.
Your Straightforward Installation Guide
Installing your new ECM is a manageable job for a seasoned DIYer or any professional technician. We handle the complex programming; you just need to perform the installation and final vehicle-side relearn procedures.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the ECM: On most trucks and SUVs like the Escalade, Tahoe, and Sierra, the ECM is located in the engine compartment on the left-hand (driver’s) side. On the Corvette, it’s under the dash on the right-hand side. Consult a service manual for your specific model if unsure.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that must be released. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed ECM into place and securely reconnect the electrical harnesses. Ensure they click into place.
- Reconnect Power: Reattach the negative battery terminal.
- Perform Security Relearn: This is the most critical step. If the vehicle does not start, you MUST perform the Vehicle Theft Deterrent (VTD) system relearn using a compatible GM diagnostic tool (such as Tis2web/Techline Connect). This syncs the new ECM with your vehicle’s security system.
- Additional Relearns: Depending on your vehicle, other procedures like a Crankshaft Position Variation Relearn or injector flow rate programming may be necessary to ensure optimal performance. This is the responsibility of the installer.
Verified Fitment for Your GM Truck, SUV, or Car
This module is a direct replacement for multiple part numbers, ensuring broad compatibility. Please verify your vehicle is on this list. This unit replaces part numbers 12692068, 12704476, 12686382, 12674052, 12674472, and 12678815.
- Cadillac ATS (2017): 3.6L, VIN Y (LF4)
- Cadillac CTS (2017): 6.2L (Supercharged) or 3.6L, VIN 8 (LF3, Twin Turbo)
- Cadillac Escalade / ESV (2017)
- Cadillac XTS (2017): 3.6L, VIN 8 (LF3)
- Chevrolet Corvette (2017)
- Chevrolet Silverado 1500 (2016-2018)
- Chevrolet Suburban 1500 (2017)
- Chevrolet Tahoe (2017)
- GMC Sierra 1500 / Denali 1500 (2016-2018)
- GMC Yukon / Yukon XL 1500 (2017)
Frequently Asked Questions
Frequently Asked Questions
What is a VTD (Vehicle Theft Deterrent) Relearn?
It’s a security procedure that syncs the new ECM to your vehicle’s ignition key and anti-theft system. It requires a professional scan tool with GM software (like Techline Connect). Without this step, the vehicle’s security system will prevent it from starting, thinking it’s being stolen.
Do I need to send you my old module?
No. We program this replacement module using the Vehicle Identification Number (VIN) you provide at checkout. There is no core charge or need to send in your old part.
Is this part truly plug-and-play?
It is ‘plug-in and program’. The complex software flashing is done for you. However, the final, on-vehicle security relearn is a mandatory step that you or your mechanic must perform. So, it’s not simply ‘plug and drive’.
What happens if I don’t provide a VIN?
We cannot ship the module without your vehicle’s 17-digit VIN. The programming is entirely dependent on this number to load the correct software and calibrations for your specific engine, transmission, and options.
How do I find my vehicle’s VIN?
Your VIN can be found on your vehicle’s registration, insurance card, or on the driver’s side of the dashboard, visible through the windshield.